Methods for well completion



Oct. 17, 1967 Filed April 29, 1965 C. P. LANMON ll METHODS FOR WELLCOMPLETION 2 Sheets-Sheet 1 C P an/77 of? INVENTOR.

Oct. 17, 1967 C; R ANMN 3,347,315

METHODS FOR WELL COMPLETION Filed April 29, 1965 2 Sheets-Sheet 2 I l QQy 153B i 7i 7 [NVE/WOR.

United States Patent O 3,347,315 METHODS FOR WELL COMPLETION C. P.Lanmon II, Friendswood, Tex., assignor, by mesne assignments, toSchlumberger Technology Corporation, Houston, Tex., a corporation ofTexas Filed Apr. 29, 1965, Ser. No. 451,857 5 Claims. (Cl. 166-23)ABSTRACT OF THE DISCLOSURE Thisapplication discloses methods forconsolidating incompetent earth formations surrounding a cased well boreand providing unobstructed fluid communication therewith. Moreparticularly, the disclosed methods are directed toward consolidating -aportion of an incompetent earth formation adjacent to a cased well boreto preclude the subsequent displacement of loose particles of formationmaterials as well as to provide relatively unobstructed fluidcommunication therewith. These methods are accomplished by rst injectinga suitable consolidating agent or agents into the particular formationbeing completed. Then, once it is believed that the injected portion ofthe formation has suciently iirmed, a perforation is made through thecasing and cement into the irmed formation portion to provide a cleanunobstructed fluid-communication path thereto.

Accordingly, as will subsequently become more apparent, this inventionrelates to methods for completing wells; and, more particularly, tomethods for inhibiting the production of sand from unconsolidated orincompetent subsurface formations.

The present trend in well completion techniques is `to rely upon onlyone or, at most, a very few perforations at each of carefully selectedpoints in -a Well rather than indiscriminately scattering a large numberof perforations along a wide interval. Where such perforations are madein a particularly loose or unconsolidated formation, sand particles andthe like, will, however, be displaced into the well bore as connatefluids are produced from the formation. Thus, unless preventativemeasures are taken, these sand particles will either settle out so as toeventually till the Well bore or be carried to the surface by theproduced fluids and severely damage production equipment. Moreover, withonly a few perforations aifording limited entry through the casing intothe formation, the production will be severely limited should any ofthese perforations become plugged.

. Accordingly, to solve this problem, apparatus and methods have beendevised whereby as soon as a loose formation is perfor-ated, a suitablebonding or consolidating agent is injected through the perforation intothe formation where, in time, it will react and harden. These agents, orso-called plastics generally coat the sand grains and thereby cementthem together. Although it will depend upon the particular agentsemployed, the pore spaces between adjacent particles are left open inone way or another so as to provide permeability. Thus, a portion of theformation surrounding the perforation is consolidated to serve as aporous support to prevent loose sand particles from entering theperforation as connate fluids are produced from the formation.

Typical of such treating agents, apparatus and methods are thosedisclosed in Patent No. 3,153,449 granted to Maurice P. Lebourg and No.3,174,547 granted to Roger Q. Fields. As described in those patents, aperforating and injecting tool is positioned adjacent a formation thatis believed to be unconsolidated. An extendible wall-engaging member isoperated to shift the tool toward one wall of the casing and sealinglyengage a sealing member on the opposite wall to isolate a portion of thewell bore from the Well control tiuids. A perforator, such as a shapedcharge, is then actuated to produce a perforation through this isolatedportion into the adjacent earth formation. Thereafter, a bonding agentis ejected from a cylinder in the tool by a displacing piston andinjected through the perforation into the formation.

The present invention is intended to provide new and improved methodsfor completing unconsolidated earth formations where the formations arerst consolidated prior to completion. Then, once the formation isconsolidated, it is completed and debris is removed from the perforationin the consolidated portion of the formation. This debris has been foundto include particles of the casing and cement as well as residue fromthe shaped charge. By removing this low-permeability debris, thesurfaces through which connate iluids must flow will be cleaned togreatly increase production ow rates.

Accordingly, it is an object of the present invention to provide new andimproved methods for consolidating an incompetent earth formation andproviding a fluid passage therein that is free of such objectionablelowpermeability debris.

This and other objects of the present invention are provided by rstisolating a surface of an unconsolidated earth formation from the wellcontrol uids in a well bore; perforating thru the isolated surface intothe formation; injecting a formation-consolidating agent into theformation under sufficient pressure to overcome the effects of debris;and, when the formation-consolidating agent is calculated to havefirmed, perforating through the isolated surfaces into the treatingportion of the formation to provide a fluid passage into the stabilizedformation and to remove the debris from the passage.

The novel features of the present invention are set forth withparticularity in the appended claims. The present invention, both as toits organization and manner of operation together with further objectsand advantages thereof, may best be understood by way of illustrationand example of certain embodiments when taken in conjunction with theaccompanying drawings, in. which:

FIG. 1 is a View depicting a well completion tool within a well bore andin position to practice the present invention;

FIG. 2 is an elevational View, partially in cross-section, of Ia portionof the tool depicted in FIG. l; and

FIGS. 3-5 are views depicting in sequence the apparatus of FIG. 1performing the methods of the present invention.

Turning now to FIG. l, a well completion tool 10 arranged to practicethe methods of the present invention is shown suspended from amulti-conductor cable 11 in a casing 12 secured within a borehole 13 bya column of cement 14. The cable 11 is spooled from a winch (not shown)at the earths surface, with some of its conductors being arranged forselective connection to a power source (not shown) and others beingconnected to indicating-and-recording means (not shown) at the surfaceof the ground.

The well completion tool 10 is comprised of an elongated body which, tofacilitate manufacture and assembly, may be arranged to include upperand lower sections 15 and 16 that are tandemly connected above and belowan intermediate section 17 having longitudinally spaced, annular,sealing means 18 and 19 on one side thereof and extendible wall-engagingmeans 20 on its opposite side.

The upper section 15 encloses a hydraulic system (not shown) forselectively actuating the extendible wall-engaging means 2G. Thishydraulic system may, for example,

be of the type illustrated in Patent No. 3,011,554, granted to RobertDesbrandes which utilizes the hydrostatic pressure of the well controluids 21 to develop an increased pressure in the system for selectivelyactuating the wallengaging means 20. Thus, upon command from thesurface, the wall-engaging means will be extended against one side ofthe casing 12 to shift the tool 10 laterally and sealingly engage thesealing means 18 and 19 against the opposite side of the casing. Then,when it is desired to retrieve the tool 10, the hydraulic pressure inthe system is relieved and the wall-engaging means 20 are retracted.

The hydraulically actuated wall-engaging means 20 are comprised of oneor more extendible pistons 22 that support a back-up shoe 23 that isnormally held in a retracted position against the setcion 17 by springs24. The pistons 22 are sealingly received within hydraulic cylinders(not shown) that are connected to the hydraulic system. Thus, wheneverthe hydraulic system is activated from the surface, the developedhydraulic pressure will urge the pistons 22 outwardly to extend theback-up shoe 23 against the casing 12. Inasmuch as the particulardetails of the hydraulic system and wall-engaging means 20 are notenecessary for fully understanding the present invention, they have beenshown only schematically in FIG. 1.

Fluid discharge means are generally housed in the intermediate section17 and include a pair of lateral chambers 25 and 26 within the sectionthat are each open at one end, with the annular sealing means 18 and 19being mounted around the open ends of these cham-bers to provide centralopenings 27 and 28. The lower chamber 26 is connected to a fluid passage29; and thin-walled closure members 30 and 31 are mounted in the chamberon each side of the open upper end of the passage 29 to block thecentral opening 28 and the rearward portion of the chamber. A shapedcharge 32 is received in the rearward portion of the chamber 26 andfaces the closure members 30 and 31 so that, upon detonation, theperforating jet will puncture the closure members and be directedthrough the central opening 28.

In a similar manner, the upper chamber 25 is connected by a fluidpassage 33 to an enclosed low-pressure or atmospheric chamber 34 in theintermediate section 17. Thin-walled closure members 35 and 36 aremounted in the upper chamber 25 on each side of the open lower end ofthe passage 23 to block the central opening 27 of the sealing means 18and the rearward portion of the chamber. A shaped charge 37 is disposedin the rear of the upper chamber 25 and directed toward the closuremembers 35 and 36 so that, upon detonation, the perforating jet willpierce the closure members and be directed through the central openings27. Suitable electrically responsive igniter means 38 and 39 (FIG. 2*),that are ignitable from the surface of the earth via conductors in thecable 11, are connected to the shaped charge 32 and 37.

It will be realized that when the lower shaped charge 32 is detonated topuncture the closure members 30 and 31 and produce a perforation into anadjacent earth formation, lluid communication will be established fromthe fluid passage 29 through the central opening 28 and into theresultant perforation. Similarly, whenever the other shaped charge 37 isdetonated, the closure members 35 and 36 will be pierced and fluidcommunication will be established from the resultant perforation throughthe central opening 27 and into the low-pressure chamber 34.

A treating agent cylinder 40 is formed in the lower section 16 andconnected by a centrally located passage 41 to a normally-open valve 42(such as that shown at 105 in the above-mentioned Desbrandes patent)connected to fluid passage 29. The treating agent injector 43 for thecylinder 40 is comprised of a slidable, hollow cylinder 44 that has aclosed lower end 45 and is telescoped over a piston 46 secured throughan elongated coaxial rod 47 to the upper end of the treating agentcylinder 40 and slidably received in the treating agent cylinder. Anannular piston 48 secured to the upper end of the slidable cylinder 44is fluidly sealed by O-rings 49 and 50 to the inner wall of the treatingagent cylinder 40 and elongated rod 47, respectively, to isolate thetreating agents in the cylinder 40 above the annular piston. An O-ring51 tluidly seals the fixed piston 46 to the inner wall of the hollowcylinder 44 to provide an enclosed low-pressure or atmospheric chamber52 therein below the fixed piston. A port 53 is provided in the wall ofthe hollow cylinder 44 to admit Well control fluids 21 into the space 54below the annular piston 48 and above the Xed piston 46.

The treating agent cylinder is divided into separate fluid-tightchambers 55-57 by spaced, floating pistons 58 and 59 that are each uidlysealed between the elongated rod 47 and inner wall of the cylinder 40.As will be subsequently explained, valves 60 and 61 (such as those inFIG. 3 of the Fields patent) in the annular floating pistons S8 and 59remain closed to segregate the treating agents in the chambers 55-57until each piston 58 and 59 has reached its upper limit of travel. Aflow restrictor 62 is placed in series with the valve 60 to regulate theflow of treating agents from the intermediate and lower chambers S6 and57.

It will be appreciated that when the cylinder 40 is lled with treatingagents, the hollow cylinder 44 and annular piston 48 will remain in theposition illustrated in FIG. 1 until the thin-walled closure member 31is punctured. Thus, until the shaped charge 32 is detonated, the forcestending to move the hollow cylinder 44 and piston 48 upwardly must equalthe forces acting downwardly thereon. Since each of these forces isequal to the product of a pressure multiplied by the effectivecross-sectional area that it acts upon, by reference to FIG. 1, theforces can be expressed as:

(Phys) (A3-Ai) -l- (Pwd-Perm) (A2) (As-"AO It will be appreciated that(A3-A1) will be very nearly equal to A2 and that Pam will be practicallynegligible. Thus, it will be realized that the pressure developed (Pdev)in the treating cylinder 40 Will be very nearly double the hydrostaticpressure (Phyd) of the well control fluids 21. Accordingly, if forexample, the ratio of developed and hydrostatic pressure is in the orderof 1.811 and the hydrostatic pressure is 10,000 p.s.i.g., it will beappreciated that the injection pressure will be 18,000 p.s.i.g. Thus, ifthe natural formation pressure is 9,000 p.s.i.g., the treating agents inthe cylinder 40 will be injected at an effective differential of 9,000p.s.i.

Accordingly, the hydrostatic pressure of the well control fluids 21 willact on the injector 43 to exert a multiplied pressure on the treatingagents in the chambers 55- 57 to sequentially discharge the treatingagents from the chambers through the fluid passage 41 thereabove. This.multiplied pressure produces a high effective differential pressurerelative to formation pressures.

A pressure transducer 63 is provided to continuously monitor thepressure in the fluid passage 29. This transducer 63 may, for example,be of the type shown in FIG. 9 of the aforementioned Desbrandes patent,and is connected by an electrical lead (not shown) via the cable 11 tothe pressure indicating-and-recording apparatus at the surface of theearth. Thus, by observing the variations in pressure measurements, anoperator will be advised of the progress of the operating cycle of thewell completion tool 10.

Turning now to FIG. 2, an elevational view, partially in cross-section,is shown of one manner in which the intermediate section 17 may bearranged with the sealing means 18 and 19 and with reference numeralsused in conjunction with FIG. 1 to identify the corresponding elements.Shaped charge chambers 25 and 26 are formed in the intermediate section17 and tilted in such a manner that their central axes intersect a shortdistance in front of the forward ends of the chambers. The shapedcharges 32 and 37 are secured and iiuidly sealed in the chambers 26 and25 behind threaded tubular members 64 and 65 having enlarged-diameterflanges 66 and 67 on their forward end. The anges 66 and 67 supportannular elastomeric sealing members 68 and 69 that are received withinforwardly facing counterbores 70 and 71 in the section 17 and iluidlysealed therein by O-rings 72 and 73. O-rings 74 and 75 around thecentral portion of the closure members 64 and 65 provide Huid-tightannular spaces 76 and 77 in the forward end of the lateral chambers 25and 26, with radial bores 78 and 79 connecting these spaces to thecentral bores 80 and 81 through the cl-osure members.

The sealing members 68 and 69 are comprised of con centrically arrangedouter and inner elastomeric rings 82-85 mounted on opposite sides ofannular reinforcing members 86 and 87. Shoulders 88 and 89 directedinwardly from the `rear of the reinforcing members 86 and 87 are securedagainst the forward faces of the tubular members 64 and 65 by theforward thin-walled closure members 31 and 36. The forwardfaces 90 and91 of the sealing means 18 and 19 are skewed in the vertical plane andcurved in the horizontal plane to ensure that they will conform to thecurvature of a casing or borehole wall. It will be appreciated that thereinforcing rings 86 and 87 will prevent the outer elastomeric rings 82and 84 from being extruded radially inwardly whenever the hydrostaticpressure of the well control fluids 21 is greater than the pressurewithin the central openings 27 and 28. Similarly, the inner elastomericrings S3 and 85 will be supported against radial outward extrusionwhenever the pressure within the central openings 27 and 28 is greaterthan that of the well control fluids 21.

The thin-wal1ed closure members 35 and 36 are spaced i apart andthreadedly secured in the central bore 81 through the upper tubularmember 65 on opposite sides of the radial bores 79 to block the centralopening 27 and isolate the shaped charge 37. The fluid passage 33connects the bore 81 between the thin-Walled closure members 35 and 36to an enlarged bore 92 thereabove that is closed at its upper end toprovide the atmospheric chamber 34, The detonating means 33 fordetonating the shaped charge 37 are comprised of a `short length ofdetonating cord 93 disposed on the rear of the shaped charge 37 that iscoupled to a conventional electrical detonator 94 received within atransverse passage 95 extending upwardly from the shaped charge chamber25. The other thin-walled closure members 30 and 31 are arranged in thesame manner and define a space in the central Ibore S0 of the lowertubular member 64 that is connected by a fluid passage 96 to the mainiiuid passage 29 in the lower section 16 (FIG. 1). The shaped charge 32is similarly detonated in the same manner by the det-onating means 38comprised of a detonating cord 97 and electrical detonator 98. Thehydraulically actuated pistons 22 are mounted in hydraulic cylinders ateach end of the section 17, with the back-up shoe 23 being normallyretracted against the rear face of the section 17.

Turning now to FIGS. 3-5, the successive steps of the method of thepresent invention are schematically illustrated as they would beperformed by the well completi-on tool 10. Although the exactarrangement will, of course, be determined by the particularconsolidating materials to be used by way of example, a pre-flush fluid99, such as a saline solution, is contained in the upper chamber 55 ofthe treating agent cylinder 40; the intermediate chamber 56 contains asuitable plastic consolidation agent 100, such as a formaline-cresolmixture, while the lower chamber 57 contains an after-flush agent 1011such as kerosene. Other consolidating agents and associated reagentsthat may be used would include those described in U.S Patents Nos.3,070,161, 3,097,692, and 3,100,527.

VAfter the treating agents 99-101 have been `deposited in the cylinder40, the tool 10 is assembled and positioned in the well bore 13 adjacenta selected formation 102. By actuating the hydraulic system, the back-upshoe 23 is extended to shift the tool laterally and sealingly engage thesealing means 18 and 19 against the casing 12. Once the sealing means 18and 19 have been firmly seated, it Will he appreciated that the centralopenings 27 and 28 in front of the thin-walled closure members 31 and 36will be isolated from the well control fluids 21 in the well bore 13. Atthis time, the hydrostatic pressure of the Well control fluids 21 willhave -displaced the pre-flush fluid 99 from the upper chamber 55 throughthe normally-open valve 42 and into the space in bore 80 between thethin-Walled closure members 30 and 31.

As best seen in FIG. 3, the lower shaped charge 32 is then detonated topuncture the thin-walled closure members 30 and 31 and produce aperforation 103 that is directed into the formation 102 in aslightlyupward ydirection. As the perforating jet punctures the closuremember 31, the pre-flush fluid 99 (which is at a high ef fectivedifferential pressure relative to the pressure of the formation fluids)will be immediately displaced into the perforation 103. As the pre-flushfluid 99 is exhausted from the upper chamber 55, it will be.` realizedthat the full pressure developed in the treating cylinder 40 by theinjector 43 will be available to inject this agent at a high flow rateinto the formation 102. Thus, by injecting the preflush fluid 99 intothe formation 102 at this elevated pressure, the agent will be able tobreak through any residue left in the perforati-on 103 by the shapedcharge 32 and enter the formation.

It will'be appreciated that although the fluid pressure Within thecentral opening 28 is higher than the hydro static pressure of the Wellcontrol fluids 21, the forward end of the reinforcing member 86 will beagainst the casing 12 and sealing member 83 will be sealed therewith.However, the reinforcing member 86 will support the sealing member 83and prevent its radially outward extrusion.

As best seen in FIG. 4, once the pre-flush fluid 99 has been expelledfrom the upper chamber 55, the upper floating piston 58 will havereached the top of the cylinder 40 to open the valve 60 therein. Then,the continued application of the developed pressure by the injector`(-13 will displace the remaining treating agents 100 and 101 incontrolled sequence-from the intermediate and lower chamber 56 and 57through the low restrictor 62 and into the formation 102. As these othertreating agents 100 and 101 are injected into the formation 102, theconsolidating plastic agent 100 will harden and, in time, consolidatethe loose formation.

It has been found that 4by injecting the rst treating agent (such as thepre-Hush iiuid 99) at a high flow rate and pressure, loose sand cannotflow back into the tool 10 and the perforation 103 will be preventedfrom collapsing. It has been found advantageous, however, to inject theother treating agents 100 and 101V more slowly and with only suicientpressure to overcome the formation pressure so that these agents willnot channel but will instead permeate and uniformly ll the interstitialvoids between the individual sand particles. It will be understood,however, that the yfull developed pressure of the injector 43 is alwaysavailable and, where a greater press-ure is needed, the iiow rate willmerely be reduced by the restrictor 62 as the pressure downstreamthereof increases.

Once the treating agents 99-101 have been exhausted, the tool 10 is leftin position, as seen in FIG. 4for a period of time calculated to besuiiicient for the plasticconsolidating material to have suilicientlyiirmed or congealed t0 form a porous barrier, as at 104, around theperforation 103. This interval of time will, of course, depend upon thesetting characteristics of the particular plastic employed. Then, oncethe plastic agent is calculated to have rmed or hardened, as best seenin FIG.

5, the upper shaped charge 37 is then detonated to produce a secondperforation 105 that either intersects the first perforation 103 orcomes in close proximity thereto. It will be appreciated that byperforating into the firmed or hardened porous portion 104 of theformation 102, the perforation 105 will not collapse. Moreover, fluidcommunication will be suddenly established through the secondperforation 105 to the atmospheric chamber 34. Thus, by suddenly openingcommunication from the formation 102 to the atmospheric chamber 34, theformation pressure will displace the connate fluids into the perforation105 and up into the atmospheric chamber and flush the debris from withinthe perforation to leave a relatively uncontaminated and stabilizedsurface. It will be realized, of course, that a conventionalnormallyclosed valve could also be employed in passage 33.

It should be noted that the sudden drop in pressure within lthe centralopenings 27 and 28 of sealing means 18 and 19 will cause the outersealing rings 84 and 82 to lrbe tightly sealed against the casing 12 bythe hydrostatic pressure. Tubular reinforcing members 86 and 87 will,however, prevent extrusion of sealing rings 82 and 84 into the centralopenings 27 and 28.

The consolidation agents used in performing the present invention may beeither porous-setting or solid-setting plastics. The invention is notlimited, however, to any particular type of sand consolidating agent solong as it is capable of ul-timately providing a porons barrier withinthe formation around the perforation through which it is ejected.Typical types of sand consolidation agents that may be used generallyinclude (1) a porous-setting type of plastic wherein a phase separationtakes place to leave hardened plastic around the sand grains and openpore spaces between the sand grains; (2) a porous-setting type ofplastic that shrinks and cracks -upon setting to form openings withinthe consolidating region to allow passage of connate fluids; (3) asolid-setting type of plastic wherein, after the plastic is injected,after-flush fluids are injected to wash away the plastic from the porespaces between sand particles to provide sufficient permeability forflow of connate fluids; and (4) a solid-setting type of plastic whereinat least two of its constituents are kept separated from one anotherwithin the treating agent cylinder 40 and are successively injected intothe formation to mix in situ.

It Will be further realized that the particular nature of the sandconsolidating agent employed will govern whether either a pre-flush oran after-flush agent are required. Thus, the treating cylinder 40 needsonly to contain whatever agents or constituents thereof and arranged inwhatever sequence that are considered to be necessary to obtain a porousconsolidated portion as at 104 that is calculated to be sufficientlyfirmed when the second shaped charge 37 is detonated that the resultantperforations 105 will not collapse. Accordingly, the present inven--tion should neither be considered as being limited to any particularone or genus if sand consolidating agents nor requiring pre-flush orafter-flush fluids unless necessary to achieve the above-mentionedfirming reaction.

Once the operation has been completed, the hydraulic system is actuatedto relieve the hydraulic pressure therein to retract the back-up shoe 23and allow the tool 10 to be withdrawn from the well bore 13.

Accordingly, it will be seen that to practice the abovedescribed methodof the present invention, the tool is positioned in the borehole 13adjacent to the formation 102 of interest. The sealing means 18 and 19are urged against the casing 12 to isolate a surface from the wellcontrol fluids 21. Then, the formation 102 is perforated, as at 103,through the isolated surface to permit injection offormation-consolidating agents, ,such as plastic 100, into the formationwhich, in time, will harden to form a porous support, as at 104,adjacent to the entry hole -through the casing 12. Thereafter, when theporous support 104 has become sufliciently firm, the formation 102 isagain perforated, as at 105, through the isolated surface to opencommunication from the last perforation to a lowpressure chamber, suchas at 34, for receiving connate fluids from the pormation 102 to flushthe perforation 105.

Thus, it will be appreciated that the present invention has provided newand improved methods for consolidating earth formations and providingfluid passages therein that are free of objectionable low-permeabilitydebris so that connate fluids `may be subsesuently produced therefrom atreasonably high flow rates without also dislodging loose formationparticles.

While particular embodiments of the present invention have been shownand described, it is apparent that changes and modifications may be madewithout departing from this invention in its broader aspects; and,therefore, the aim in the appended claims is to cover all such changesand modifications as fall within the true spirit and scope of thisinvention.

What is claimed is:

1. A method of completing a cased Well bore containing a column of wellcontrol fluids and traversing an earth formation believed to includeunconsolidated particles, comprising the steps of: perforating through acasing and into a formation believed to include unconsolidated particlesto provide a first passage therein; injecting a formation-consolidatingagent into said first passage for consolidating unconsolidated formationparticles within a zone contiguous with said first passage; and, whensaid formation-consolidating agent is calculated to have firmed,perforating through the casing and into said consolidated .formationzone to provide a second passage calculated to terminate therein.

2. A method of'completing a cased Well bore containing a column of wellcontrol fluids and traversing an earth formation believed to includeunconsolidated particles, comprising the steps of: packing-off a casingto isolate a portion thereof from the well control fluids; perforatingthrough a casing and into a formation believed to include unconsolidatedparticles to provide a first passage therein; injecting aformation-consolidating agent into said first passage for consolidatingunconsolidated formation particles within a zone contiguous with saidfirst passage; when said formation-consolidating agent is calculated tohave firmed, perforating through the casing at said isolated portion andinto said consolidated formation zone to provide a second passagecalculated to terminate therein; and withdrawing debris from said secondpassage.

3. A method of completing a cased well bore containing a column of wellcontrol fluids and traversing an earth formation believed to includeunconsolidated particles comprising the steps of: packing-off first andsecond portions of a casing from the well control fluids; perforatingthrough the casing at said first isolated portion and into a formationbelieved to include unconsolidated particles to r provide a firstpassage therein; injecting a formationconsolidating agent into saidfirst passage for consolidating unconsolidated formation particleswithin a zone contiguous with said first passage; when saidformationconsolidating agent is calculated to have firmed, perforatingthrough the casing at said second isolated portion and into saidconsolidated formation zone to provide a second passage calculated toterminate therein; and withdrawing debris from said second passage intosaid receiver.

4. A method of completing a cased well bore containing a column of wellcontrol fluids and traversing an earth formation believed to includeunconsolidated particles comprising the steps of: packing-off first andsecond portions of a casing to isolate said first and second portionsfrom the well control fluids; perforating through the casing at saidfirst isolated portion and into a formation believed to includeunconsolidated particles to provide a first passage therein; injecting aformation-consolidating agent into said first passage for consolidatingunconsolidated formation particles within a zone contiguous with saidfirst passage; when said formation-consolidating agent is calculated tohave irmed, perforating through the casing at said second iso-latedportion and into said consolidated formation zone to provide a secondpassage calculated to terminate therein; and reducing the pressure atsaid second isolated portion to produce connate fluids from theformation for flushing debris from said second passage.

5. A method of completing a cased well bore contain ing a column of wellcontrol fluids and traversing an earth formation believed to includeunconsolidated particles, comprising the steps of: packing-ofrp rst andsecond portions of a casing to isolate said portions from the Wellcontrol fluids and from one another and positioning a receiver at areduced pressure adjacent to one of said isolated portions and a sourcecontaining a formationconsolidating agent adjacent to the other of saidisolated portions; perforating through the casing at said other isolatedportion and into a formation believed to include unconsolidatedparticles to provide a first passage therein; injecting saidformation-consolidating agent from said source and into said firstpassage for consolidating unconsolidated formation particles Within azone contiguous with said rst passage; when said formation-consolidatingagent is calculated to have tirmed, perforating through the casing atsaid one isolated portion and into said consolidated formation zone toprovide a second passage calculated to terminate therein; andestablishing fluid communication between said second passage andreceiver for discharging debris from said second passage into saidreceiver.

References Cited UNITED STATES PATENTS 20 CHARLES E. OCONNELL, PrimaryExaminer.

DAVID H. BROWN, Examiner.

1. A METHOD OF COMPLETING A CASED WELL BORE CONTAINING A COLUMN WELLCONTROL FLUIDS AND TRAVERSING AN EARTH FORMATION BELIEVED TO INCLUDEUNCONSOLIDATED PARTICLES, COMPRISING THE STEPS OF: PERFORATION THROUGH ACASING AND INTO A FORMATION BELIEVED TO INCLUDE UNCONSOLIDATED PARTICLESTO PROVIDE A FIRST PASSAGE THEREIN; INJECTING A FORMATION-CONSOLIDATINGAGENT INTO SAID FIRST PASSAGE FOR CONSOLIDATING UNCONSOLIDATED FORMATIONPARTICLES WITHIN A ZONE CONTIGUOUS WITH SAID FIRST PASSAGE; AND, WHENSAID FORMATION-CONSOLIDATING AGENT IS CALCULATED TO HAVE FIRMED,PERFORATION THROUGH THE CASING AND INTO SAID CONSOLIDATED FORMATION ZONETO PROVIDE A SECOND PASSAGE CALCULATED TO TERMINATE THEREIN.